1 Field of the Invention
The present invention is directed generally to optical fiber for telecommunications and more specifically to Stimulated Brillouin scattering (SBS) suppressed optical fiber for nonlinear applications.
2 Technical Background
Stimulated Brillouin Scattering (SBS) is a dominant nonlinear penalty in many optical transmission systems. In many systems, the launching of large power to optical fiber while maintaining high signal to noise ratio (SNR) is desirable. However, as the launch power or signal power of an incident signal launched into an optical fiber increases, the launch power may exceed a certain threshold power and part of the signal power is reflected due to SBS as a reflected signal. An undesirably large amount of the signal power can thus be reflected back toward the transmitter due to SBS. In addition, the scattering process increases the noise level at the signal wavelength. The combination of decrease in signal power and increase in the noise both lower the SNR and lead to performance degradation.
Nonlinear applications utilizing known small effective area optical fibers are typically limited by the SBS threshold of the optical fiber. Typically the SBS limit is encountered before reaching the desired nonlinearities. Furthermore, known nonlinear fibers typically have a high dopant level in order to achieve a small effective area, but the high dopant level leads to increased losses due to Rayleigh scattering.